Synthesis, crystal structures, and thermal properties of rhodium(iii) complexes with γ-picoline and isonicotinic acid

The complex salts [Rh(γ-Pic)4Cl2]X, where X = Cl, ReO4, or ClO4, were synthesized and characterized by IR spectroscopy, elemental analysis, X-ray powder diffraction, and single-crystal X-ray diffraction. The salts containing the ReO4− and ClO4− ions are isostructural. The oxidation of the γ-picoline complexes afforded a complex with isonicotinic acid. The crystalline product of the oxidation reaction was isolated and characterized by X-ray diffraction. The crystal structure contains two types of rhodium complex cations, which differ in the number of oxidized γ-picoline molecules. Thermal transformations of the complexes were studied by DTA, as well as by DTA coupled with evolved gas analysis. The thermolysis products were isolated and studied by IR and NMR spectroscopy.